Is it possible to build solar farms in space?
In 1941, the famous science fiction writer Isaac Asimov published a short story "Reason." This is a warning story about robots and artificial intelligence. Its peculiar background setting is still being talked about today. It is a space station that can collect solar energy and transfer energy to planets through microwaves.
An orbital solar farm drawn by a NASA artist in 1999. Like many other space solar designs, this facility requires many connected components, which means that launch costs will be very high
After this work, the use of space-based solar energy has become an enduring novel idea. If humans can master this technology and raise funds to realize it, the human world may change as a result.
Donald Buren is one of the wealthiest real estate developers in the United States. He has also read some books on solar energy. He is able to provide financial help for this project. The California Institute of Technology has recently announced that since 2013, Donald Buren and his wife Brigitte have donated more than $100 million to the school to help the realization of orbital photovoltaic power generation.
This magnificent project will require a lot of money, and more importantly, related work has been going on for more than ten years. A team at the California Institute of Technology plans to launch a test array for the first time in late 2022 or 2023.
The high earth orbit is a good place to build solar farms, because here the sun will never set and there will never be shadowing clouds. However, in order to generate a large amount of electricity, most of the previous designs are impractical. Not only are they large in scale, but also costly, which cannot be afforded by the current human society. In the description of engineers, there are huge truss structures, usually several kilometers long; photovoltaic panels or mirrors are installed on the trusses to absorb or concentrate sunlight, convert light energy into direct current, and then transmit it to the ground through laser or microwave beams. The construction of such a device may require hundreds of rocket launches. In the eyes of many people, this is destined to be a technology that is too large to succeed.
What really needs to be done is a technical paradigm shift. We are not talking about a weight of 1 kilogram per square meter, but a system that can be manufactured today with only 100 to 200 grams per square meter. The technical roadmap for this project hopes to reduce this range to 10 to 20 grams per square meter.
So, how will this roadmap be achieved? Of course it cannot be done overnight, but we can change our thinking. Perhaps the biggest change is to make modular solar panels. Lightweight gallium arsenide photovoltaic cells will be connected to "tiles"-the basic unit of solar panels designed by the California Institute of Technology-each "tile" may be only 100 square centimeters in size, equivalent to a dessert plate.
The key is that each "tile" is itself a miniature solar power station, equipped with photovoltaic devices, miniature electronic components and microwave transmitters. All the "tiles" will be connected together to form a larger "module", which may reach an area of 60 square meters. Thousands of modules will form a hexagonal power station with each side 3 kilometers long. There is even no physical connection between these modules, no heavy support beams and bundled cables, and less mass.
You can think of it as a school of fish, like a large group of the same independent elements flying in formation. Next, the energy transmission to the ground receiver will be achieved through synchronized phased array microwave signals so that they can be aimed without moving parts. This transmission is inherently safe, because microwave energy is not ionizing radiation, and its energy density will be "equal to the power density in sunlight."
It may take several years to realize solar power generation in space. Analysts at the American Aerospace Corporation’s Space Policy and Strategy Center warned that this "will not be a quick, simple or comprehensive solution." From Internet satellites to plans to return to the moon and land on Mars, the cost of space launches is gradually decreasing, and new spacecraft are constantly being launched. Ground power grids may not be the first users of solar satellites, and there will be more demand for this. It is other space vehicles, after all, it will be more practical to receive microwave beams from solar power fields in orbit than to have your own solar panels.
News source: cnBeta